Respiratory Energy Losses in Podophrya fixa Muller in Relation to Temperature and Nutritional Status

Abstract

Respiration in well-fed and starved P. fixa was measured using Cartesian diver microrespirometry at 5.degree. C intervals between 10.degree.-30 C. At 10.degree. C encystment occurred. The optimum temperature for respiration was 25.degree. C where a rate of 41.3 .times. 10-6 .mu.l h-1 per individual was recorded in well-fed animals. Mean cell size reached a maximum at 25.degree. C in well-fed individuals. Respiratory rate and mean cell size decreased with starvation, as did the rate of metabolism. A table of daily respiratory energy losses in well-fed and starved Podophyra was presented. Results and their implications were discussed in relation to other Protozoa.